Embodiments of the present invention relate to a sense-amp transistor of a semiconductor device, and more particularly to a sense-amp transistor of a semiconductor device and a method for manufacturing the same, which can minimize the number of additional processes by improving a gate structure of the sense-amp transistor, thus increasing a sensing margin.
A sense amplifier (hereinafter referred to as a sense-amp) of a semiconductor device includes a pull-up element using a PMOS transistor and a pull-down element using an NMOS transistor, such that it amplifies a data voltage loaded on a bit line (BL) and a bit line bar (/BL) and outputs the amplified result to a data bus.
FIG. 1 is a circuit diagram illustrating a pull-up element and a pull-down element of a sense-amp for use in a semiconductor device.
Referring to FIG. 1, the sense-amp of the semiconductor device includes PMOS transistors (P1, P2) and NMOS transistors (N1, N2), that are complementarily coupled to one another in the form of a cross-coupled latch between a pull-up voltage (RTO) and a pull-down voltage (SB). A gate of the PMOS transistor P1 and a gate of the NMOS transistor N1 are coupled to a bit line (BL), and a commonly connected drain of the PMOS and NMOS transistors P1 and N1 is coupled to a bit line bar (/BL). A gate of the PMOS transistor P2 and a gate of the NMOS transistor N2 are coupled to the bit line bar (/BL), and a commonly connected drain of the PMOS and NMOS transistors P2 and N2 is coupled to the bit line (BL).
FIG. 2 is a plan view illustrating a sense-amp shown in FIG. 1.
Referring to FIG. 2, an active region 10, in which four transistors are to be formed, is formed in a square shape, and a gate of each transistor constructing the sense-amp is in a ring shape in the active region 10.
Transistors constructing the sense-amp shown in FIG. 2 have been designed to use a recess gate structure to increase a current.
However, recently, as the integration degree of semiconductor devices increase and cell size gradually shrinks, the sense-amp area also shrinks.
However, since a conventional sense-amp allows a gate of each transistor to be configured in the form of a recess gate, and uses a ring-type gate structure as the recess gate, it is difficult to shrink the sense-amp area.
In addition, in the conventional sense-amp a channel was formed only in a recessed channel region, so that it may be difficult to guarantee the sensing margin when the size of the semiconductor device is reduced.